Here is the full list of all 26 Obludia achievements.
Die 50 times
Fire 100 Shotgun Shells
Cast 50x Ring of Fire spell
Slay 30 Ghosts.
Slay 20 Devils.
Cast 50x Glacial Spike spell
Throw 50 dynamites.
Complete World 3 – Frozen Island
Use 10x Holy Cross.
Cast 50x Lightning Strike spell
Complete World 5 – Space Ship
Destroy 50 Alien eggs
Save 10 princess.
Complete World 4 – Hell Gate
Slay 100 monsters with blade.
Find 20 chest.
Complete World 2 – Ancient Tower
Find 1000 Coins.
Slay 20 chickens.
Eat 20 Hamburger.
Complete World 1 – Dungeon of Doom
Find the legendary golden monkey statue
Complete the game on HARD mode.
Buy your first dog.
Slay your first enemy.
Complete the game.